Diamond bearing for high-speed drag bits

Abstract

A bearing for a rotary cone for a rock bit is disclosed. The bearing consists of a multiplicity of small synthetic diamond particles nested within a matrix base, each with an exposed flattened surface to form the bearing. The diamond particles are strategically positioned on a bearing surface and secured within the matrix base. A substantially identical synthetic diamond bearing is concentrically positioned adjacent to the first bearing to form the bearing package.

What is claimed is: 
     
       1. A diamond bearing for a rotary rock bit comprising: a main bit body forming a first pin end and a second cutting end, said bit body further forms a chamber therein open to said first pin end to direct a source of coolant through said bit body;   at least one support means for a rotary cutter adjacent said second cutting end of said bit, said support means forming a journal with bearing surfaces thereon;   a rotary cutter mounted on said journal, said rotary cutter forming bearing surfaces opposing respective bearing surfaces formed by said journal; and   said bearing surfaces having a multiplicity of separated diamond segments strategically positioned on and around said bearing surfaces, each of said diamond segments having at least one flat surface substantially aligned with a surface formed by said bearings, each of said diamond segments is attached to its respective bearing surface by a matrix material metallurgically bonded to said bearing surface, said source of coolant is directed through a passage formed between said bit body and said bearing surfaces to cool said diamond bearing segments during operation of said rotary rock bit.   
     
     
       2. The invention as set forth in claim 1 wherein said journal formed by said support means for said rotary cutter and said rotary cutter each form a plurality of concentric, oppositely opposed axial and cylindrical bearing surfaces. 
     
     
       3. The invention as set forth in claim 1 wherein said journal formed by said support means for said rotary cutter and said rotary cutter each form concentric, oppositely opposed conical bearing surfaces. 
     
     
       4. The invention as set forth in claim 1 wherein means for cooling is at least one flow channel formed by said first bearing surface. 
     
     
       5. The invention as set forth in claim 4 wherein said at least one flow channel formed by said first bearing surface is spirally oriented along substantially the entire length of said bearing. 
     
     
       6. The invention as set forth in claim 5 wherein a second flow channel is formed by an opposite second bearing surface. 
     
     
       7. The invention as set forth in claim 6 wherein said second flow channel formed by said second bearing surface is spirally oriented along substantially the entire length of said bearing surfaces. 
     
     
       8. The invention as set forth in claim 7 wherein said second spirally oriented flow channel formed by said second bearing surface has its spiral orientation opposite to said spirally oriented flow channel in said first bearing surface. 
     
     
       9. The invention as set forth in claim 1 wherein said diamond segment shapes are selected from a group consisting of triangles, cubes, tetrahedrons and spheres, each segment of which forms at least one flat surface. 
     
     
       10. The invention as set forth in claim 1 wherein said diamond segments are cubical diamond segments having a flat surface substantially aligned with a surface formed by said bearing. 
     
     
       11. The invention as set forth in claim 10 wherein said cubical diamond segments are sized to substantially conform to a bearing diameter such that when a multiplicity of separated and strategically positioned cubical diamond segments are positioned and attached within said matrix their multiplicity of flats, when combined around the circumference of said bearing surface, essentially conform to said curved bearing surface. 
     
     
       12. The invention as set forth in claim 11 wherein when said bearing diameter is about two inches in diameter each of said cubical diamond segments is about 0.055 inches. 
     
     
       13. The invention as set forth in claim 1 wherein said matrix material attaching said diamond segments therein is a tungsten carbide matrix. 
     
     
       14. The invention as set forth in claim 13 wherein said tungsten carbide matrix consists essentially of tungsten carbide particles and a binder of nickel-silver. 
     
     
       15. The invention as set forth in claim 13 wherein said tungsten carbide matrix consists essentially of tungsten carbide particles and a binder of nickel-manganese-copper. 
     
     
       16. The invention as set forth in claim 13 wherein said tungsten carbide matrix consists essentially of tungsten carbide particles and a binder of chrome-nickel-boron. 
     
     
       17. The invention as set forth in claim 16 wherein said multiplicity of strategically positioned cubical diamond segments attached by said matrix are separated one from another by sufficient tungsten carbide particles to provide enough porosity to assure capillary infiltration of said binder. 
     
     
       18. The invention as set forth in claim 17 wherein said matrix separation between said diamond cubes is from 150 to 300 microns. 
     
     
       19. The invention as set forth in claim 1 wherein said diamond segment is synthetic polycrystalline diamond. 
     
     
       20. The invention as set forth in claim 19 wherein said synthetic polycrystalline diamond material is thermally stable. 
     
     
       21. The invention as set forth in claim 1 wherein said diamond segment is natural diamond. 
     
     
       22. A diamond bearing comprising a multiplicity of separated cubical diamond segments strategically positioned on said bearing, each of said cubical diamond segments having a flat surface substantially aligned with a surface formed by said bearing, said cubical diamond segment is attached to said bearing surface by a metallurgical matrix material bonded to said bearing surface. 
     
     
       23. The invention set forth in claim 22 wherein said cubical diamond segment is a thermally stable polycrystalline diamond. 
     
     
       24. The invention as set forth in claim 22 wherein said metallurgical matrix material is comprised essentially of tungsten carbide particles and a binder of nickel-silver. 
     
     
       25. The invention as set forth in claim 22 wherein said metallurgical matrix material is comprised essentially of tungsten carbide particles and a binder of nickel-manganese-copper. 
     
     
       26. The invention as set forth in claim 22 wherein said metallurgical matrix material is comprised essentially of tungsten carbide particles and a binder of chrome-nickel-boron. 
     
     
       27. The invention as set forth in claim 26 wherein each of said strategically positioned cubical diamond segments attached by said matrix is separated, one from the other, by from 150 to 300 microns.